A human rights commission has accused Mexican investigators of stalling in their inquiry into the disappearance of 43 students in 2014.
The Inter-American Commission on Human Rights (IACHR) is conducting its own probe in the country.
Dozens of arrests have been made since the teaching students went missing after they were attacked and captured in September 2014. But the exact fate of the students remains unknown.
The group says it has no information on open investigations into irregularities involving Mexican authorities looking into the case.
IAHCR members have endorsed harsh criticism of the investigation carried out by international experts. It led to the resignation of a top prosecutor who conducted the initial inquiry and was suspected of manipulating evidence.
The group has rejected the prosecution’s initial findings that the youths were killed and burned in a rubbish dump in the town of Cocula, near Iguala. The current prosecutor says different hypotheses are being investigated.
The Attorney General’s Office (PGR) says it has followed the experts’ recommendations, but still has no relevant results.
“We have clearly expressed our concerns over the problems in speeding up investigations, and we are concerned that there have not been any new findings since December 2015 – and that regarding the police in Huitzuco up to now no formal accusation has been made,” said Paulo Abrao, the IAHCR’s Executive Secretary.
Parents of the victims and their lawyers believe investigators have failed to probe the role the army could have had in the young people’s disappearance. Some parents believe their children are still alive and being held captive.
Family members of the the missing have kept up a permanent protest outside the headquarters of Mexico’s Attorney General to keep up the pressure on the authorities.
“Here we are and if they come to kill us we will face them. We are not scared, we are full of anger. That is how it will be,” said Epifanio Alvarez, the father of a missing student.
In line with a local tradition, the student teachers commandeered buses, planning to go to a protest in Mexico City. They came under attack from police and unidentified gunmen in Iguala in Guerrero state.
Some were killed; the government’s version was that the missing were turned over to a heroin trafficking gang.
Exactly what happened is unknown amid suspicion of collusion between gangsters, police, local authorities and possibly investigators.